Generally, the aim of papermaking is to manufacture paper which corresponds to the quality desired by a customer. Paper quality may be expressed with several different parameters, such as tensile strength, basis weight and surface properties of the paper. The above-mentioned paper-technical properties of paper depend on several factors, including the quality of the paper pulp used for papermaking, for example. Paper pulp is used in papermaking by feeding pulp onto the wire of a paper machine and by drying the pulp into paper. Paper pulp may be manufactured by, for example, chemically or mechanically separating cellulose from wood. Pulp may also be manufactured of recycled fibre, such as newsprint, by means of a recycled fibre process. Further, it is obvious that the paper quality depends, to a great extent, on different operations of the paper machine producing the paper.
Paper pulp is thus an intermediate product used in manufacturing paper, paperboard or board, containing fibre suspension, such as cellulose, minerals and chemicals. However, most of the paper pulp is water, which disperses the fibre and makes it pliable.
Since paper pulp may be produced in several different ways and there are several different processes affecting its manufacture, it is obvious that paper pulps produced in different ways may have very different properties. Therefore, a paper-technical property of paper, paperboard or board produced as an end product may vary a lot, depending on the properties of the paper pulp used. It is thus extremely challenging to assess the value of a paper-technical property of an end product if the quality of the paper pulp cannot be determined accurately. There have been attempts to solve this problem by keeping the quality of paper pulp stable and, in this way, to obtain paper, paperboard or board of given quality.
A problem in the arrangement described above is that keeping the properties of paper pulp stable is challenging, and when a customer wishes to have paper, paperboard or board of given quality, searching for properties of paper pulp providing the desired quality is work that takes time and resources. Thus, in order to produce an end product of the desired type and quality, it is important to provide a solution by means of which this is possible without excessively wasting resources.